title: Differentiating primary progressive aphasias in a brief sample of connected speech.
abstract: OBJECTIVE
  A brief speech expression protocol that can be administered and scored without special training would aid in the differential diagnosis of the 3 principal forms of primary progressive aphasia (PPA): nonfluent/agrammatic PPA, logopenic variant PPA, and semantic variant PPA.
  
  
  METHODS
  We used a picture-description task to elicit a short speech sample, and we evaluated impairments in speech-sound production, speech rate, lexical retrieval, and grammaticality. We compared the results with those obtained by a longer, previously validated protocol and further validated performance with multimodal imaging to assess the neuroanatomical basis of the deficits.
  
  
  RESULTS
  We found different patterns of impaired grammar in each PPA variant, and additional language production features were impaired in each: nonfluent/agrammatic PPA was characterized by speech-sound errors; logopenic variant PPA by dysfluencies (false starts and hesitations); and semantic variant PPA by poor retrieval of nouns. Strong correlations were found between this brief speech sample and a lengthier narrative speech sample. A composite measure of grammaticality and other measures of speech production were correlated with distinct regions of gray matter atrophy and reduced white matter fractional anisotropy in each PPA variant.
  
  
  CONCLUSIONS
  These findings provide evidence that large-scale networks are required for fluent, grammatical expression; that these networks can be selectively disrupted in PPA syndromes; and that quantitative analysis of a brief speech sample can reveal the corresponding distinct speech characteristics.
authors.affiliation: Department of Neurology, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, USA. ash@mail.med.upenn.edu
authors.forename: Sharon
authors.initials: S
authors.lastname: Ash
authors.forename: Emily
authors.initials: E
authors.lastname: Evans
authors.forename: Jessica
authors.initials: J
authors.lastname: O'Shea
authors.forename: John
authors.initials: J
authors.lastname: Powers
authors.forename: Ashley
authors.initials: A
authors.lastname: Boller
authors.forename: Danielle
authors.initials: D
authors.lastname: Weinberg
authors.forename: Jenna
authors.initials: J
authors.lastname: Haley
authors.forename: Corey
authors.initials: C
authors.lastname: McMillan
authors.forename: David J
authors.initials: DJ
authors.lastname: Irwin
authors.forename: Katya
authors.initials: K
authors.lastname: Rascovsky
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018888:Aphasia, Primary Progressive / Q000145:classification* / Q000175:diagnosis / Q000503:physiopathology*; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D005260:Female; D057180:Frontotemporal Dementia / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012660:Semantics; D013060:Speech / Q000502:physiology*